MusicaltechMusicaltech specialize in top digital audio concepts using powerful programmable logic devices. Original designs include total replacement of off-the-shelf chips - seen by the Musicaltech team as a limitation in performance and flexibility. Information about one of the the most sophisticated dacs avaialable for DIYers, either multibit or delta-sigma, are available in the dedicated forum.

I already have an apodizing filter available. I can supply the dac with it, instead of linear phase. Another option - which sound best of all to my ears - is a convolution FFT type, which is impulse response optimized - somewhat a combination between minimum phase and linear.

I like the choice of the filters. This way one can avoid pre-ringing of the linear filter.

How is the USB done and is the USB part isolated from the rest of the DAC?

I like the choice of the filters. This way one can avoid pre-ringing of the linear filter.

How is the USB done and is the USB part isolated from the rest of the DAC?

Can you PM me the prices?

Thanks,

Tony

The USB makes use of a Cypress hi-speed interface which outputs paralell data. Then data is serialized internally into the fpga after a fixed clock. The usb isolation is appealing to some degree but right now means also bandwidth limiting, so we decided not to use it - and frankly I don't miss it in this design; the sound on usb input is just stunning.

This looks like something I've been after for a few years, a good way to find out if the pcm1704 is what people say it is!

How do we swap filters / update the software? I understand it is probably not easy to expose all this via USB to the PC but is there another way in? an interface for us to remotely update and swap filters (provided by you)?

This looks like something I've been after for a few years, a good way to find out if the pcm1704 is what people say it is!

How do we swap filters / update the software? I understand it is probably not easy to expose all this via USB to the PC but is there another way in? an interface for us to remotely update and swap filters (provided by you)?

Thanks

The filters are simply switched with the remote using the dedicated menu entry.
You can switch between 2 types for now - you can specify me the type of filter(s) wanted.

I already have an apodizing filter available. I can supply the dac with it, instead of linear phase. Another option - which sound best of all to my ears - is a convolution FFT type, which is impulse response optimized - somewhat a combination between minimum phase and linear.

I'm looking for a copy of the apodizing filter and also some prints with dimensions like the rd30 so I can case this up.